If forces balance then the object is in equilibrium
Make sure to check if object is drawn to scale
B
The principle makes some sense; the more that a force is directed upwards (the angle with the horizontal increases), the less that the force is able to exert an influence in the horizontal direction
As the angle that a force makes with the horizontal increases, the component of force in the horizontal direction (Fx) decreases
Can use soh/cah/toa to find the components of a vector
D
Normal force not always equal to gravitational force
The principle is that the vertical forces must balance if there is no vertical acceleration. If an object is being dragged across a horizontal surface, then there is no vertical acceleration. For this reason, the normal force (Fnorm) plus the vertical component (Fy) of the applied force must balance the gravitational force (Fgrav).